Less than three weeks to go. In the National League, it's all about seeding, while the American League still offers two earnest division battles and at least a five-team bout for two Wild Card spots.

A multitude of questions remain in these races, but these are the five most prominent at the moment.

1. Have the Astros' road woes caught up to them?
Sunday's astounding and unlikely comeback in Anaheim was awesome, but it was also an anomaly. The bottom line is that the Astros are 9-25 on the road since July 4 (only the Braves have fared worse), and their latest road loss -- 5-3 to the Rangers on Monday night -- cut their division lead to a half-game.

Obviously, the Astros are a very home run-reliant club, and the current absence of Carlos Gomez because of an intercostal issue only exacerbates the issue. At home, 17.4 percent of Houston's fly balls go for home runs. On the road, it's just 11.4 percent, which means theirs is a fundamentally different offense in ballparks that don't feature trains full of oranges (note to the Astros: start traveling with trains full of oranges).

After the series with Texas concludes on Thursday, Houston won't be on the road again until the final week of the season. There's some yin and yang on that final road trip, with three games at the suppressive Safeco Field and the season-ending Interleague set in the supportive environment of Chase Field. Park factors are an especially important factor with this Astros club, and it will be interesting to see how much those final-week factors play a part in a scintillating AL West race.

Rasmus' game-tying single

HOU@TEX: Rasmus singles off Moreland, ties the game

9/14/15: Colby Rasmus rips a single that bounces off Mitch Moreland, scoring Carlos Correa to tie the game at 3

2. Will the schedule decide the NL Central?
For Pittsburghers -- or just those of us who picked the Pirates to win the NL Central -- a number of aligning factors are encouraging. The Bucs have won 20 of their past 30 games. That surge has placed them within 2 1/2 games of a Cardinals club that had looked uncatchable before their recent funk, in which they've dropped eight of 11.

With the recent returns of A.J. Burnett to the rotation and Josh Harrison and Jordy Mercer to the lineup, the Pirates are back to full strength, and the experience of having a promising 2014 season snuffed out in one night by Madison Bumgarner in the NL Wild Card Game gives them all the incentive they need to try to finish with a flourish. Of course, with four games against the Cubs this week -- and seven in all in the next 12 days -- the Bucs are met with an equally motivated match over the next two weeks.

While the Pirates and Cards do have one more head-to-head series remaining (Sept. 28-30 in Pittsburgh), the Cardinals clearly have the softer schedule down the stretch. Thirteen of the Cards' final 19 games will be against the Brewers, Reds and Braves, owners of three of the NL's five lowest winning percentages. The Bucs do have series remaining against the Rockies and Reds, but for whatever reason, Cincinnati has been an awful matchup for them the past two years. They are 6-10 against the Reds this year and were 7-12 against them last season.

Beyond the recent struggle to generate runs, St. Louis could be running into fatigue issues with Carlos Martinez, who has pitched past the fifth inning in just three of his past eight starts. And Jaime Garcia, at 104 1/3 innings, has entered innings terrain he hasn't reached since 2012. So the Cardinals aren't exactly cruising to the finish line like it once appeared they would.

But at the very least, the schedule sets up nicely for St. Louis.

Pham's two-run homer

STL@CIN: Pham belts a two-run homer for the lead

9/13/15: Tommy Pham breaks a tie in the 6th inning with a two-run home run to left off Sam LeCure, giving the Cardinals a 4-2 lead

3. How big of a deal is the Troy Tulowitzki injury?
Tulo was on the verge of his first injury-free season in four years before the collision with Kevin Pillar on Saturday. Now, he's out at least two to three weeks with a cracked left shoulder blade, and the Blue Jays will scramble to replace his defensive impact. Give credit to general manager Alex Anthopoulos for his on-the-ball handling of the various middle-infield injury conundrums posed on his club, and the early August addition of Cliff Pennington, as well as the weekend swap with the Dodgers for Darwin Barney, at the very least gives Toronto options down the stretch, allowing Ryan Goins to shift from second base to short.

Personally, I don't think Tulo's absence is enough to swing the AL East in the direction of a Yankees team dealing with injury issues of its own. Offensively, the Blue Jays are well equipped to carry on without their starting shortstop, as he was only generating a .232/.314/.368 slash line since his arrival from Colorado. In fact, Goins had outperformed Tulo since the trade (.268/.371/.390). But how quickly Tulo recovers and his comfort level upon his return could be big keys come October, because his defensive presence is a big deal to Toronto's pitching staff.

Tulo's RBI single

TOR@NYY: Tulo singles in Encarnacion to extend lead

9/11/15: Troy Tulowitzki singles to left field, driving in Edwin Encarnacion to give the Blue Jays a 3-0 lead in the top of the 1st inning

4. What does Matt Harvey have left in the tank?
Not in terms of innings but stuff. We know the innings will be limited. For the second time in the past month, Harvey will have a double dose of rest before his next outing against the Yankees this weekend, and the Mets will keep him on a short leash from here on out.

But is the Harvey the Mets are trotting out there the same pitcher we've come to know and love? He has given up 11 runs on 17 hits in 11 2/3 innings this month. Interestingly, per Brooks Baseball, Harvey has gravitated away from the slider -- a pitch that has been known to increase the rate of elbow injuries -- as the season has evolved:

Brooks Baseball's data also indicates that Harvey has grooved his slider much more consistently in 2015 than he did in 2013.

Because Harvey's September showing is such a small sample (with the first start affected by dehydration issues), it's not worth rushing to any judgment about what we've seen. With or without Harvey, the Mets are going to win the NL East. But if Harvey is dealing with fatigue or any other issue that affects his usage patterns and performance, where will he slot into the Mets' postseason plans? (You might have read somewhere that Harvey, who in his spare time is a New York bureau chief for an up-and-coming Internet publication, intends to pitch in the postseason.)

MLB Central: Harvey's role

MLB Central discusses Harvey's role down the stretch

The guys debate if Matt Harvey throwing half outings to finish the season will hurt his chances of starting in the playoffs for the Mets

5. Time to take the Tribe seriously?
All facets of the remaining AL Wild Card race are interesting, but the Indians, who have won 16 of 23 to climb four games in the loss column for the last October spot, are a particular source of curiosity given that they were such clear sellers at the Trade Deadline.

My personal policy on the Tribe has been, "Call me when they get to .500." And after Monday night's win over the Royals, the phone is ringing. The Indians have been a totally different team on the defensive end since shortstop Francisco Lindor and third baseman Giovanny Urshela arrived in June, and in the stretch run, they've gotten unexpected impact from low-profile trade acquisition Abraham Almonte in center field and from former Quad-A castoff Lonnie Chisenhall in his new home in right.

Almonte's grand slam

LAA@CLE: Almonte belts a grand slam to right-center

8/30/15: Abraham Almonte hits a grand slam to right-center field off Jered Weaver, increasing the Indians' lead to 6-0

Corey Kluber's return to the rotation on Thursday, after a brief bout with hamstring woes, seems to have real meaning in the standings. The Tribe still has seven games remaining against the Twins, so there are plenty of head-on opportunities against one other Wild Card contender. Still, the Indians will need some help out West.

Entering the week, Baseball Prospectus was giving Cleveland a 12-percent shot at a postseason berth, which is pretty incredible for a club that was 10 games under .500 just 39 days ago.